The present invention relates to an image signal processing apparatus, an imaging apparatus, and an image processing program, for example, to an image signal processing apparatus to conduct a noise correction and various image corrections to change signal levels.
The background of the present technique is, for example, JP-A-2010-278937. According to the technique described in JP-A-2010-278937, the object thereof is to achieve high contrast in low-luminance and high-luminance portions while suppressing noise in the luminance portion and to achieve high contrast in feature portions of an image. Further, an image signal processing apparatus includes first region input/output characteristic control means 3 for controlling variation in input/output characteristics for each optional region while being interlocked with a value of an input luminance signal, first region luminance signal correcting means 1 for varying input/output characteristics of a luminance signal in accordance with output of the first region input/output characteristic control means, second region input/output characteristic correcting means 2 for controlling variation in input/output characteristics for each optional region while being interlocked with output of the first region luminance signal correcting means, second region luminance signal correcting means 2 for varying input/output characteristics of a luminance signal in accordance with output of the second region input/output characteristic control means, color signal input/output characteristic control means 5 for controlling variation in input/output characteristics of an input color signal by utilizing the output of the first region input/output characteristic control means and the output of the second region input/output characteristic control means, and color signal correcting means 6 for varying input/output characteristics of a color signal in accordance with output of the color signal input/output characteristic control means.